ISO 17502:2013

Overview

ISO 17502:2013 is an international standard developed by the International Organization for Standardization (ISO) that specifies a precise method for determining the surface reflectance properties of leather across visible and near-infrared radiation wavelengths. This standard focuses on measuring the diffuse reflectance factor of leather surfaces, particularly at 900 nm, which is critical for classifying leather as solar reflective.

The measurement method described in ISO 17502:2013 applies to all leather types, with an emphasis on colored leathers, and is essential for evaluating leather used in applications where solar reflectivity impacts user comfort and material performance.

Key Topics

• Measurement Scope: Reflectance properties of leather surfaces in the visible (400–700 nm) and near-infrared (700–1100 nm) spectral ranges, specifically focusing on the 900 nm wavelength for solar reflectance classification.

• Solar Reflective Leather: Leather that reflects at least 55% of incident radiation at 900 nm is classified as solar reflective. This reflectance reduces heat absorption, improving comfort in automotive interiors, footwear, and other applications exposed to sunlight.

• Measurement Principle: Utilizing a spectrophotometer equipped with an Ulbricht integrating sphere, ISO 17502 defines a standardized technique for accurately capturing the diffuse reflectance factor of leather surfaces, minimizing errors due to surface texture and pigmentation.

• Equipment and Calibration:

  • Spectrophotometer with an integrating sphere (30 mm diameter) and appropriate spectral range (400–1100 nm).
  • Reference white standard with reflectance >98% across 250–1500 nm to calibrate the instrument.
  • Fiber optic cables connecting light source, integrating sphere, and detector for optimal light transmission.
  • Calibration against black and white references to ensure accuracy and repeatability.

• Sample Preparation and Testing Procedure:

  • Dry leather specimens approximately 300 mm × 200 mm are prepared.
  • Specimens are placed flat with the exposed surface oriented upwards.
  • Reflectance measurements at 900 nm are taken at multiple locations on the sample, with averages computed and significant variation (>10%) noted.

• Reporting Requirements: Test reports must include the leather type, surface tested, measured reflectance at 900 nm, classification regarding solar reflectivity, testing deviations, and test dates.

• Measurement Fidelity: Repeatability within ±2% under the same lab conditions and inter-laboratory variability within ±4% at the 55% reflectance threshold, ensuring reliability for quality control and research.

Applications

ISO 17502:2013 provides significant practical value in several areas:

• Automotive Interiors: Evaluating leather used in car seats and trim to ensure reduced heat build-up and enhanced passenger comfort under solar exposure.

• Footwear Manufacturing: Identifying reflective properties of leather for shoes designed for outdoor or high-temperature environments to prevent overheating.

• Leather Finishing and Dyeing: Assisting manufacturers in selecting pigments and finishing processes that influence near-infrared reflectance for optimized leather performance.

• Material Certification and Quality Control: Offering a standardized method for suppliers and buyers to assess leather surface reflectance consistently, facilitating compliance with solar reflectivity requirements.

• Environmental and Energy Efficiency: Promoting the use of solar-reflective leather to reduce energy consumption related to cooling in automotive and architectural applications.

Related Standards

• ISO 2418 – Leather - Chemical tests for color fastness to artificial light sources, relevant for assessing color stability under solar exposure.

• ISO 17075 – Leather - Chemical tests - Determination of chromium content, relevant for ensuring safe tanning processes influencing leather surface properties.

• ISO 6507 – Metallic materials - Vickers hardness test, complementary when assessing mechanical properties in conjunction with surface treatments.

• ISO 7724 – Paints and varnishes - Color measurement, related to surface color analysis which correlates with reflectance characteristics.

• CEN/TC 289 Standards – European leather testing standards often harmonized with ISO, providing additional methodologies in leather testing.

Keywords: ISO 17502, leather surface reflectance, solar reflective leather, near-infrared reflectance, Ulbricht integrating sphere, spectrophotometer method, leather testing standard, leather reflectivity measurement, colored leather, solar heat management, leather quality control.